As an X-ray emitting target, a transmission type target is publicly known. In the transmission type target, an electron emission source and an extraction window can be arranged on a straight line, so that the transmission type target is expected to be applied to a small-sized X-ray emitting device.
PTL 1 discloses that when a tungsten anode is formed on a diamond substrate, an adhesion promoting layer is disposed as an intermediate layer between the anode and the diamond substrate. PTL 2 discloses that when a tungsten anode is formed on a beryllium substrate, an intermediate layer of copper, chromium, iron, titanium, or the like is disposed between the anode and the beryllium substrate in order to prevent peeling due to stress caused by the difference between the linear expansion coefficients.